1. Field of the Invention
The invention pertains to the art of sealing arrangements for sealing the ends of arcuate segments arranged in an annular array and located in an environment subject to substantial temperature changes. The invention may be particularly well employed in the art of gas turbine construction.
2. Description of the Prior Art
The advantage of minimizing leakage of cooling air flow from the diaphragm assemblies composed of a number of stator segments into the motive fluid path in a gas turbine is well known. Examples of patents dealing with sealing arrangements for such devices are U.S. Pat. Nos. 3,542,483 and 3,519,366, which teach arrangements of sealing strips provided to bridge the gaps between the opposing ends of adjacent stator segments. The sealing strips taught in these patents are single metal pieces which have their opposite longitudinal edge portions received in facing grooves provided in the opposing faces of adjacent stator segments. Such seal arrangements, while effective to a relatively high degree, do not provide as adequate a seal as is believed desirable. The problem arises from the requirements of machining and assembly tolerances which result in clearances through which cooling air can flow into the motive fluid path during operation of the turbine.
Therefore an aim of this invention is to provide an improved seal arrangement for the joints between the segments of a turbine diaphragm assembly.